A surface where a shaft and a hole having the same nominal diameter contact with each other is a coupling interface for cylindrical fitting, hereinafter referred to as the coupling interface for cylindrical fitting. The coupling interface for cylindrical fitting is classified into two categories, i.e., fixed coupling interfaces for cylindrical fitting (for example, a press fitting of a shaft and a hole) and motional coupling interfaces for cylindrical fitting, wherein the motional coupling interfaces for cylindrical fitting are further classified into slewing motional coupling interfaces for cylindrical fitting (for example, the slewing motional coupling interface for cylindrical fitting between a shaft and a hole of a slewing and sliding bearing) and rectilinear motional coupling interfaces for cylindrical fitting (for example, the rectilinear motional coupling interface for cylindrical fitting between a cylinder and a piston).
At present, the rigidity of the coupling interface for cylindrical fitting is generally obtained through analytic method, and the reliability of the analytic method and an analyzed result should be verified via tests, however, since the coupling surfaces for cylindrical fitting exist in a test system, and the rigidity thereof is non-linear, the requirements on method and device for the tests are very strict, the loading and testing method thereof should ensure the implementation of the expected model, the characteristics of the coupling interface for cylindrical fitting as the tested object need to be separated from the characteristics of the test system, so as to ensure the accuracy of the test. Thus the rigidity test related to such coupling interface is greatly limited due to complicated method and apparatus structure and high cost.